On the day of this offence I was standing in front of the sheriff's office at 505 Main St., Which is a block south and just around the corner from the building from which the shots were fired. Just a few seconds after the president's car had passed my location I heard a shot ring out, a couple of seconds elapsed and then two more shots ring out. I inmmediately ran to the area from which it sounded like the shots had been fired. This is an area between the railroads and the Texas School Book Depository which is east of the railroads. There were several other officers in this area and we secured it from the public. After searching this area for about ten minutes and not finding any evidence, I went to a tower that overlooks the railroad yards and also has a vantage point over the area around the school book building. I talked to an employee there and he gave me the description of two automobiles that he had seen in the area just a few minutes earlier. When I went back outside I learned from other officers that it had been established that the shots were fired from the school book building. I went to the building and found that several officers were inside and others were gathering outside. I then went back to the street and mixed with the crowds trying to get people who were witnesses to the tragedy. After I had brought several people to the office I went to TV Station WFAA and got two witnesses who had been taken there by some reporter. A while later a City of Dallas policeman came to our office with three prisoners who he had arrested on the railroad yards. I took these three to the city jail and turned them over to Capt. Fritz. I then came back to the sheriff's office where I remained the rest of the day talking to witnesses and taking statements.